One of the less glamorous but necessary tasks performed by Fleet Air Arm aircraft was the fleet spotting and reconnaissance undertaken by aircraft catapulted by capital ships.
Specification S.11/32 for such an aircraft attracted a tender from Fairey for a biplane floatplane with a crew of two. The design was unusual in that the pilot sat in an open cockpit while the observer/gunner was in an enclosed rear cockpit, an arrangement designed to facilitate catapult launches and the subsequent recovery of the aircraft from the sea by crane. Construction was mixed, the fuselage being a metal monocoque, while the wings were fabric-covered. Fairey's bid was accepted, and a contract for 49 aircraft to be named Seafox was awarded in January 1936, with a follow-on contract for a further 15 in September the same year.
As originally designed the Seafox was to have a 500-hp Bristol Aquila radial engine, but for some obscure reason the Napier Rapier 16-cylinder 'H' air-cooled engine of only 395 hp was chosen, and the Seafox was consequently underpowered throughout its life. The first prototype flew at Hamble on 27 May 1936, while the second, with wheel landing gear, followed on 5 November 1936.
Production Seafoxes began to come off the assembly line in 1937, the first flying on 23 April. Meanwhile the prototypes were being tested at the Marine Aircraft Experimental Establishment at Felixstowe, and at the Royal Aircraft Establishment at Farnborough. Felixstowe's report, not issued until the aircraft had been in service for some months, commented favourably on the handling aspects but was critical of the engine cooling and high landing speed: about 58 mph (93 km/h), instead of the 46 mph (74 km/h) which had been specified. On take-off at high weights the lack of power was particularly evident, and the Seafox showed a marked reluctance to get up 'on the step', particularly on calm water.
Catapult tests at the RAE with one of the prototypes in March 1937 were followed by trials on board HMS Neptune off Gibraltar. At the outbreak of WWII, Seafoxes equipped a number of cruisers, sharing their tasks with Walrus amphibians and Swordfish seaplanes, and it was not long before they were in action against the German pocket battleship Admiral Graf Spee during the action in the River Plate in December 1939. One of the two Seafoxes from HMS Ajax was catapulted and spotted for the guns, the first such occassion in WWII, and winning for its pilot, Lt Dewin, the first Fleet Air Arm decoration of the war.
Seafox production had ended in 1938, but the type continued in front-line service until about 1942, when it was replaced by the Vought-Sikorsky Kingfisher. Even then, a few Seafoxes lingered on the training role until July 1943.